core,eth,internal/ethapi,les: Extend API Backend to subscribe dropped txs

This extends the API Backend interface and respective implementations with
the ability to subscribe to dropped and rejected transactions.

core/tx_pool.go

@@ -428,9 +428,9 @@ func (pool *TxPool) SubscribeDropTxsEvent(ch chan<- DropTxsEvent) event.Subscrip
 	return pool.scope.Track(pool.dropTxFeed.Subscribe(ch))
 }
 
-// SubscribeRejectedTxsEvent registers a subscription of RejectedTxEvent and
+// SubscribeRejectedTxEvent registers a subscription of RejectedTxEvent and
 // starts sending event to the given channel.
-func (pool *TxPool) SubscribeRejectedTxsEvent(ch chan<- RejectedTxEvent) event.Subscription {
+func (pool *TxPool) SubscribeRejectedTxEvent(ch chan<- RejectedTxEvent) event.Subscription {
 	return pool.scope.Track(pool.rejectTxFeed.Subscribe(ch))
 }
 

eth/dropped_tx_subscription.go

@@ -0,0 +1,21 @@
+// This file extends the EthAPIBackend with functions for BlockNative's dropped
+// transaction feeds.
+//
+// As this is part of a fork, and not included in core geth, keeping it in a
+// separate file helps protect against potential merge conflicts. If this were
+// ever to be merged into core geth, it should be relocated to ./api_backend.go
+
+package eth
+
+import (
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/event"
+)
+
+func (b *EthAPIBackend) SubscribeDropTxsEvent(ch chan<- core.DropTxsEvent) event.Subscription {
+	return b.eth.TxPool().SubscribeDropTxsEvent(ch)
+}
+
+func (b *EthAPIBackend) SubscribeRejectedTxEvent(ch chan<- core.RejectedTxEvent) event.Subscription {
+	return b.eth.TxPool().SubscribeRejectedTxEvent(ch)
+}

internal/ethapi/backend.go

@@ -73,6 +73,8 @@ type Backend interface {
 	Stats() (pending int, queued int)
 	TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)
 	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
+	SubscribeRejectedTxEvent(chan<- core.RejectedTxEvent) event.Subscription
+	SubscribeDropTxsEvent(chan<- core.DropTxsEvent) event.Subscription
 
 	// Filter API
 	BloomStatus() (uint64, uint64)

les/dropped_tx_subscription.go

@@ -0,0 +1,31 @@
+// This file extends the LesApiBackend with functions for BlockNative's dropped
+// transaction feeds.
+//
+// As this is part of a fork, and not included in core geth, keeping it in a
+// separate file helps protect against potential merge conflicts. If this were
+// ever to be merged into core geth, it should be relocated to ./api_backend.go
+
+package les
+
+import (
+	"errors"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/event"
+)
+
+type unimplementedSubscription struct{}
+
+func (s *unimplementedSubscription) Unsubscribe() {}
+func (s *unimplementedSubscription) Err() <-chan error {
+	ch := make(chan error, 1)
+	ch <- errors.New("Subscription type not implemented")
+	return ch
+}
+
+func (b *LesApiBackend) SubscribeDropTxsEvent(ch chan<- core.DropTxsEvent) event.Subscription {
+	return &unimplementedSubscription{}
+}
+
+func (b *LesApiBackend) SubscribeRejectedTxEvent(ch chan<- core.RejectedTxEvent) event.Subscription {
+	return &unimplementedSubscription{}
+}